import Vue from 'vue'
import { VuetifyBreakpoint } from 'vuetify/types'

/**
 * A modified version of https://gist.github.com/cb109/b074a65f7595cffc21cea59ce8d15f9b
 */

/**
 * A Vue mixin to get the current width/height and the associated breakpoint.
 *
 *   <div v-if="$breakpoint.smAndDown">...</div>
 *
 */
export default Vue.extend({
  data: () => ({
    clientHeight: getClientHeight(),
    clientWidth: getClientWidth(),
    resizeTimeout: undefined as number | undefined
  }),

  computed: {
    breakpoint (): VuetifyBreakpoint {
      const xs = this.clientWidth < 600
      const sm = this.clientWidth < 960 && !xs
      const md = this.clientWidth < (1280 - 16) && !(sm || xs)
      const lg = this.clientWidth < (1920 - 16) && !(md || sm || xs)
      const xl = this.clientWidth >= (1920 - 16)

      const xsOnly = xs
      const smOnly = sm
      const smAndDown = (xs || sm) && !(md || lg || xl)
      const smAndUp = !xs && (sm || md || lg || xl)
      const mdOnly = md
      const mdAndDown = (xs || sm || md) && !(lg || xl)
      const mdAndUp = !(xs || sm) && (md || lg || xl)
      const lgOnly = lg
      const lgAndDown = (xs || sm || md || lg) && !xl
      const lgAndUp = !(xs || sm || md) && (lg || xl)
      const xlOnly = xl

      let name
      switch (true) {
        case (xs):
          name = 'xs'
          break
        case (sm):
          name = 'sm'
          break
        case (md):
          name = 'md'
          break
        case (lg):
          name = 'lg'
          break
        default:
          name = 'xl'
          break
      }

      return {
        // Definite breakpoint.
        xs,
        sm,
        md,
        lg,
        xl,

        // Useful e.g. to construct CSS class names dynamically.
        name,

        // Breakpoint ranges.
        xsOnly,
        smOnly,
        smAndDown,
        smAndUp,
        mdOnly,
        mdAndDown,
        mdAndUp,
        lgOnly,
        lgAndDown,
        lgAndUp,
        xlOnly,

        // For custom breakpoint logic.
        width: this.clientWidth,
        height: this.clientHeight
      }
    }
  },

  created () {
    if (typeof window === 'undefined') return

    window.addEventListener('resize', this.onResize, { passive: true })
  },

  beforeDestroy () {
    if (typeof window === 'undefined') return

    window.removeEventListener('resize', this.onResize)
  },

  methods: {
    onResize (): void {
      clearTimeout(this.resizeTimeout)

      // Added debounce to match what
      // v-resize used to do but was
      // removed due to a memory leak
      // https://github.com/vuetifyjs/vuetify/pull/2997
      this.resizeTimeout = window.setTimeout(this.setDimensions, 200)
    },
    setDimensions (): void {
      this.clientHeight = getClientHeight()
      this.clientWidth = getClientWidth()
    }
  }
})

// Cross-browser support as described in:
// https://stackoverflow.com/questions/1248081
function getClientWidth () {
  if (typeof document === 'undefined') return 0 // SSR
  return Math.max(
    document.documentElement!.clientWidth,
    window.innerWidth || 0
  )
}

function getClientHeight () {
  if (typeof document === 'undefined') return 0 // SSR
  return Math.max(
    document.documentElement!.clientHeight,
    window.innerHeight || 0
  )
}